Rules say the track must be put to use if the project fails. But Amtrak officials are uneasy with that role.

When the Obama administration gave California $3.4 billion in startup money for a high-speed rail system, it insisted on a guarantee that the project would not become a white elephant -- something critics could brand as a train to nowhere.

The first section of track had to run down the spine of the Central Valley and have another use, should the rest of the bullet train project collapse.

Those requirements are now at the center of an intensifying political battle, waged by critics who say the state's fallback plan to use a 130-mile stretch of track for slower Amtrak service is a sham because there's no guarantee the national rail service will ever use it.

Amtrak said it has no agreement to operate on the track and has not analyzed the possible negative effects on one of its most successful rail lines. Still, the California High Speed Rail Authority has estimated 45 minutes could be shaved off Amtrak's current service between Bakersfield and Merced.

For The Record Los Angeles Times Wednesday, December 28, 2011 Home Edition Main News Part A Page 4 News Desk 1 inches; 39 words Type of Material: Correction Bullet train: In the Dec. 27 LATExtra section, a map with an article about a possible alternative use of the first leg of California's high-speed rail track in the Central Valley incorrectly identified the city of Hanford as Hanover.

"Our purpose is to build a high-speed rail system between Northern and Southern California," said Tom Umberg, the chairman of the California High Speed Rail Authority. "But if there are any delays, I believe the track will have independent utility and provide increased efficiencies in the Central Valley."

In a letter sent last year to the authority, Amtrak officials said they supported the project and interim use of the high-speed corridor. They cited potential improvements in travel time and reliability but also cautioned that cost issues and a need for faster locomotives would have to be addressed.

But now Amtrak says it has no commitment to use the track and has not been directly involved in the planning of the route. No cost-benefit analysis or detailed studies have assessed how switching to the bullet train track, which may veer around existing stations, would affect current service.

Officials note that the state has invested millions of dollars to improve the San Joaquin Valley line and build ridership, which now ranks among Amtrak's five most traveled routes.

Without a viable alternative use for the bullet train's first segment, the controversial decision to start building in the Central Valley is likely to draw more political fire. Rep. Devin Nunes (R-Tulare), who is seeking to kill the project, called the assertion that high-speed rail construction would benefit Amtrak "a lie."

The bullet train agency plans to starting building the first section next year between Bakersfield and Merced and finish the work in 2017. But no high-speed service would operate on the line partly because there is insufficient funding for signals, maintenance facilities and an electrical system to power the trains. Another $20 billion or more in funding will be needed to begin running trains to L.A. or the Bay Area.

Starting construction in the Central Valley is growing more controversial as the project nears a groundbreaking late next year. At least four local governments in the Central Valley are rebelling, fearing the effect on their communities. Also, agricultural interests are gearing up for a major legal battle against the plan, while critics in urban areas question why the project is not starting in a major population center with severe traffic congestion.

At a recent hearing by the House Transportation and Infrastructure Committee in Washington, key California legislators asked if the construction plan could be changed. But Joseph Szabo, the Obama administration's chief of the Federal Railroad Administration, said California has no flexibility to rethink the project.

"The ability to shift dollars is not there," he said.

Roelof van Ark, the project's chief executive, insists the bullet-train corridor will not become a white elephant.

He has conceded, however, that re-routing Amtrak would be relatively expensive for the benefit.

The federal government has set aside $108 million to link the high-speed segment to the track used by Amtrak, which it shares with freight hauler Burlington Northern Santa Fe Railroad. High-speed rail officials say that's enough for the job.

But a number of rail experts said that more money will be needed to integrate the two systems, and it's unclear how the financially struggling Amtrak system would pay any difference.

Amtrak officials said they have "not been directly involved in the design or development of the system." They added that they have "made no commitments to [the] idea to move the popular San Joaquin service from its present route."

The current service uses diesel-powered trains and runs from Bakersfield north to Stockton, where rail connections can be made to Oakland or Sacramento. Stops include Fresno, Hanford, Wasco and Corcoran, where many passengers stop to visit prisoners at a state correctional facility.